1. Field of the Invention
The present invention relates to a fat metabolism improving agent. More specifically, the present invention relates to a fat metabolism improving agent for reducing fat in the body, in particular, fat accumulated in the viscera (visceral fat) and fat accumulated in the liver (or for improving fatty liver) by activating metabolism of lipid in the liver, which is a site for consuming fat accumulated in the body.
2. Description of the Related Art
Obesity is not only a simple cosmetic problem but also one of important risk factors in lifestyle-related diseases such as diabetes, fatty liver, hyperlipemia, and hypertension. In other words, obesity is regarded as a preliminary step leading to development of these lifestyle-related diseases. As a method for treating or preventing obesity, dietetic treatment, therapeutic exercise, pharmacotherapy, and the like have been proposed or practiced. However, all of these methods impose physical and mental pains, e.g., side effects such as disorders due to malnutrition and disturbance of motility, hunger sensation, and stress. Thus, it is difficult to preserve the effectiveness of these methods, and furthermore, these methods often are harmful to health.
For preventing obesity, numerous attempts to prevent obesity through treatments or preventive treatments in the medical field or foods consumed on a daily basis have been made heretofore. For example, as materials having an effect of promoting metabolism or consuming of fat or an effect of suppressing accumulation of body fat, extract from algae (Japanese Laid-Open Patent Publication No. 2000-72642), fruit polyphenol (Japanese Laid-Open Patent Publication No. 10-330278), conjugated polyene fatty acid (Japanese Laid-Open Patent Publication No. 2000-355538), mixture of specified amino acids and a xanthine derivative (Japanese Laid-Open Patent Publication No. 10-330264), phospholipid from soybean and egg yolk (Japanese Laid-Open Patent Publication No. 10-84880), diterpene compound (Japanese National Publication No. 2001-508801), and the like have been proposed.
However, none of these materials can provide sufficiently satisfactory obesity preventing effect or fat metabolism improving effect because, for example, the obesity preventing effect or the fat metabolism improving effect is actually small when the materials are used alone; the materials are based on the results of impractical, brief experiments; and it is necessary to ingest the materials in a large amount in regular dietary patterns.